To investigate the differences in the co-voting behavior before and during the polarization eras, we labeled networks from Congress 40 - 99 as taking part of the “non-polarized” era, and labeled networks from Congress 100 - 113 as taking part of the “polarized” era. The split of these two samples at Congress 100 represents the theoretical and empirical evidence that polarization in the Senate emerged around the Clinton administration (Congress 103) [1]}, [2]}.
